With the development of high temperature technology such as iron and steel smelting, the development and research of high-quality and efficient refractory materials and raw materials is imminent, and synthetic raw materials are more and more applied as a refractory material with a development future. Ferrosilicon nitride (Fe-Si3N4) is a new synthetic material that has appeared in recent years. It is prepared from FeSi75 ferroalloy by nitriding technology and high temperature synthesis process.
2. Test process
Ferrosilicon nitride contains Si3N4 phase, and has some excellent properties of Si3N4, such as high refractoriness, good erosion resistance, high mechanical strength, good thermal shock resistance, low thermal expansion rate, high oxidation resistance and a series of advantages; It also has good sintering properties because it contains Fe plastic phase. At the same time, compared with silicon nitride, the price of ferrosilicon nitride is lower, and it is also easy to industrialization and production, so it has been used as a raw material for refractory materials, high temperature binding phase and high temperature structural materials, and has been widely used in blast furnace iron groove castable and mud. In recent years, more and more research has been done on ferrosilicon nitride and its application in refractories, and some achievements have been made. In this paper, the synthesis and properties of ferric silicon nitride and its application in castable, clay and composite refractories are introduced, and its prospect is also discussed.
At present, ferrosilicon nitride is mainly used in castable, clay and composite refractory materials.
1. Castable
The application of ferrosilicon nitride in castable mainly focuses on Al2O3-SiC-C iron groove castable, magnesium castable and high aluminum castable.
1.1 Al2O3-SiC-C iron groove castable
Al2O3-SiC-C castable has good slag erosion resistance and erosion resistance, and has been widely used in the main ditch, skimmer and branch ditch of blast furnace. However, due to the development of smelting technology, the continuous improvement of blast furnace utilization coefficient and the requirements of blast furnace longevity, the further improvement of the life of Al2O3-SiC-C iron groove castable is also urgent. Al2O3-SiC-C castable at the present stage is prone to fall off under the action of periodic slag, chemical attack of molten iron, thermal shock and scouring of slag and iron. At the same time, the oxidation of silicon carbide and carbonaceous materials in the castable at high temperature will also cause the structural damage of the material, which will lead to the damage of the castable.